kfence.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 3 * powerpc KFENCE support.
 4 *
 5 * Copyright (C) 2020 CS GROUP France
 6 */
 7
 8#ifndef __ASM_POWERPC_KFENCE_H
 9#define __ASM_POWERPC_KFENCE_H
10
11#include <linux/mm.h>
12#include <asm/pgtable.h>
13
14#ifdef CONFIG_PPC64_ELF_ABI_V1
15#define ARCH_FUNC_PREFIX "."
16#endif
17
18extern bool kfence_early_init;
19extern bool kfence_disabled;
20
21static inline void disable_kfence(void)
22{
23	kfence_disabled = true;
24}
25
26static inline bool arch_kfence_init_pool(void)
27{
28	return !kfence_disabled;
29}
30
31static inline bool kfence_early_init_enabled(void)
32{
33	return IS_ENABLED(CONFIG_KFENCE) && kfence_early_init;
34}
35
36#ifdef CONFIG_PPC64
37static inline bool kfence_protect_page(unsigned long addr, bool protect)
38{
39	struct page *page = virt_to_page((void *)addr);
40
41	__kernel_map_pages(page, 1, !protect);
42
43	return true;
44}
45#else
46static inline bool kfence_protect_page(unsigned long addr, bool protect)
47{
48	pte_t *kpte = virt_to_kpte(addr);
49
50	if (protect) {
51		pte_update(&init_mm, addr, kpte, _PAGE_PRESENT, 0, 0);
52		flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
53	} else {
54		pte_update(&init_mm, addr, kpte, 0, _PAGE_PRESENT, 0);
55	}
56
57	return true;
58}
59#endif
60
61#endif /* __ASM_POWERPC_KFENCE_H */